Conventionally, a vacuum cleaner includes a blower motor for making a vacuum state and an envelope-type filter in a main body, so that sludge is introduced into the main body of the cleaner by the vacuum power generated by driving the motor, and filtered by the filter, making filth residue in the main body of the cleaner, thereby only the air passing through the filter deflates through a deflation hole provided in an upper part of the main body.
The conventional filter has disadvantages that it is impossible to remove the gas including minute dust of odor, since the conventional filter provided in the main body of the cleaner as described above is made of mat-shape porous net, so that it filters merely the sludge having relatively large-sized particles, which is introduced into the main body of the cleaner by the vacuum power.
Therefore, the conventional filter as the above has defects that it can collect and discard only trash, but fails to remove contaminants substantially, and to prevent the air from contaminating since the minute dust, gas, and odor are deflated through the deflation hole when air is deflated after collecting the sludge. Especially, it has been worried about fire or explosion due to sparks generated by the cleaner motor etc., because the filters can not purify inflammable gas, harmful gas and so on, in case that these gases are sucked into the cleaner. Therefore, it is difficult to use the cleaner in the place where the inflammable gas or harmful gas would be generated, and it has to comprise extra purification devices to remove the gas, dust and odor.